CVE-2026-105306

A flaw was found in the Dynamic Client Registration flow of the Keycloak identity and access management server. The issue occurs because the registration process fails to filter security-sensitive client attributes when a new client is created. An attacker with a valid Initial Access Token can register a client that bypasses audience checks during token introspection. This allows the attacker to view sensitive identity information, roles, and session details from access tokens belonging to other applications in the same realm.

  • Published Oct 5, 2026
  • CVSS 6.5 medium
  • 0.2% chance of exploitation in the next 30 days (EPSS)

Affected software

CVE-2026-105306 at the National Vulnerability Database